Improvement in steam rock-drills



UNITED STATES JOSEPH O. GITHENS,

on NEW Y'O'IY'KT'N'. YT

IMPROVEMENT IN STEAM ROCK-DRILLS.

Specification forming part of Letters Patent No. 158,060, dated December 22, 1374; application filed October 31; 1874.

To all whom it may concern:

Be it known that I, Josnrn G. GIrHnNs, of the city, county, and State of New York, have invented a new and useful Improvement in Steam Rock-Drills, of which the following is a specification:

Figure l is a detail longitudinal section of my improved rock-drill. Fig. 2 is a detail cross-section of the same, taken through the line an ac, Fig. 1. Fig. 3 is a detail longitudinal section of a modified form of the piston and piston-rod. Fig. 4 is a detail cross-sectlzii on gt the same, taken through the line 3 3 Similar letters of reference indicate corre sponding parts.

The invention will first be fully described, and then pointed out in the claims.

A is the steam-cylinder, which is provided with a steam-inlet, B, and a steam-outlet, O. The inlet B leads into the port D, one end of which opens into the center of the cylinder A, and its other end opens into the valveohamber E, and is always covered by the cavity of the valve F. G G2 are two ports, the inner ends-of which open into the cylinder A near its ends. The other ends of the ports G G open into the valve-chamber E, and are alternately covered and uncovered by the cavity of the valve F, and being thus alternately inlet and exhaust ports, the outlet G leading out directly from the said valve-chamber E. H is the piston, which is made long, and the middle part of which is recessed, as shown in Figs. 1 and 2, to form a chamber, 71/. The recess or chamber h is made of such a length that the port D will always open into it, and will be always open. The chamber h thus serves as a steam-chest, and is the only steamchest connected with the cylinder A'. I l are two ports, the inner ends of which open into the cylinder A about midway between the ports D and the ports G G as shown in Fig. 1, so that they will be opened when the chamber h comes over them, as the piston moves back and forth in making its stroke. The other ends of the ports I 1 open into the alternate ends of the valvechamber E. By this arrangement of ports, as the piston H in making its down-stroke uncovers the port 1 the steam from the steam-chest 71/ passes through the said port I enters the alternate end of the valve-chamber E, and forces the piston J to move in the same direction as the piston H. The middle part of the piston J is made small, and fits into a groove in the top of the valve F, the sides of said valve F resting against the shoulders of the said piston J, so that the movements of the piston J will carry the valve F with it, opening the port G and allowing the steam to enter beneath the piston H and drive it back, the steam above the said piston passing out through the port G the valve-chamber E, and the exhaust or outlet 0. As the piston H, in rising, uncovers the port 1 the piston J and valve F are moved in the other direction, to admit steam through the port G and exhaust it through the port G and so on. The piston J is perforated longitudinally, and has small chambers formed in it near its ends, in which are placed valves K, the stems L of which pass through the perforations of said piston J, and meet or abut against each other in its center. From the chambers of the piston J, ports M lead through the middle ports of said piston J, and open into the valve-chamber E, and serve as exhaust-ports for the steam at the ends of the piston J. With this construction, as the steam enters at either end of the piston J, to move said piston and shift the valve F, it at the same time passes through the hole in the end of the piston J, and presses the valve K inward, closing the port M. The inward movement of the valve K causes the end of its stem L to press against the end of the stem L of the other valve K, and forces the said other valve K outward, uncovering the other port M, and allowing the steam at the other endof the said piston J to escape around the said other valve K, and through the port M, into the valve-chamber F. N is a crosshead arm, the cross-head of which rests in notches in the top of the valve E. The other end of the arm N rests in a seat at the center of the piston O, that works in the upper part of the valve-chamber E, and is held down by steam introduced above it through the port P, which opens into the inlet B, as shown in Figs. 1 and 2. The valve F is thus held down by steam-pressure, and is thus prevented from jumping when shifted.

It will be observed that when the valve F is directly over the port D, and is thus exposed to the full upward pressure of the steam, the arm I? is in a position at right angles with the valve F, and-that when the arm N is in an inclined position the steam-pressure is relieved by the opening of one or the other of the ports G G The piston H is perforated from its upper end to receive the twisted or spiral guide-rod Q. The guide-rod Q, may be made triangular or of other form in its cross-section, and enters the perforation of the piston H through a similarly-shaped nut, It, secured in the end of said perforation. V The outer part of the rod Qis made'round, passes out through a hole in the cylinder-head, and has a disk, S, attached to its outer end. The disk S and a piston, T, placed above it are covered by a cap, U, securely attached to the upper end of the cylinder A. The cavity or chamber of the cap U is made a little deeper than the thickness of the disk S and piston T, so that the said piston may have a little play, and the piston T is packed to prevent the passage of steam around it. Upon the lower side of the piston T is formed a V-shaped ring, rib, or flange, t, which enters a corresponding V- shaped ring-groovein the adjacent side of the disk S. \V is a port leading from the cavity of the cap U above the piston T to the lower port G X are ports leading from the bottom of the groove in the disk S, through the said disk, into the cavity of the cylinder A. By this construction, when the steam is admitted through the port G to raise the piston H, a part of the steam passes through the port W into the cap U, and forces the piston T downward, pressing the \l-iiange of the piston T into the V-groove of the disk S, so as to hold the disk S and the guide-rod Q stationary during the upward movement of the piston H, thus compelling said piston to turn as it moves upward. As the steam is admitted through the port G into the upper part of the cylinder A, to drive the piston H downward, a part of said steam passes through the ports X into the groove of the disk S and forces the piston T upward, the steam above said piston escaping through the portWinto the exhaustport G This allows the disk S and guiderod Q, to turn freely, so that the piston H will descend without turning. Y is the piston-rod, which passes out through the cylinder-head, and with the lower end of which the drill is connected. The piston-rod Y may be formed solid with the piston H, as shown in Fig. 1, or it may be detachable and secured in the piston H by a wedge or draw-key, as shown in Fig. 3. The latter construction I prefer, as it enables the lower end of the piston-rod Y to be made larger at its lower end, where it first fails, and also enables the chuck Z to be made a solid'part of the said rod, as shown in Figs. 3 and 4.

Having thus described my invention, Iclaiin as new and desire to secure by Letters Patent 1. The combination of the disk S, having a V shaped ring-groove formed in its upper side, the piston T, having a \I-shaped ring, rib, or flange formed upon its lower side, and the cap U, with the cylinder A, and with the spiral or twisted guiderod Q for the piston H, to cause said piston H to turn as it moves upward, and allow it to move downward without turning, substantially as herein shown and described.

2. The port W and the portsX, in connection with the port G the cylinder A, the flanged piston T, and the grooved disk S, to forcesaid piston and disk together and apart by steam, for holding and releasing the guide-rod Q as the piston H moves up and down, all combined substantially as herein shown and described.

JOSEPH G. GITHENS.

Witnesses:

JAMES T. GRAHAM, T. B. MosnER. 

